Crystal Clark was a fellow student at Trumaine University who was enlisted by Bud fo pose as the cover girl of the Girls of Trumaine calendar he created for a entrepenural studies class assignment in the Season Ten episode of Married with Children titled Calendar Girl. Crystal was played by actress Krista Allen.

When Kelly brings home a boy calendar and Bud comes up with an idea: he'll make a Girls of Trumaine calendar. Thus, he enlists the lovely Crystal. During an interview, Bud thinks that she'll ask him to marry her, even doing a pose with one knee on the ground. However, he does not know the personal secret of Crystal, that she was, in fact, a transsexual. When Crystal reveals her true gender on a local TV talk show, the shocked Bud, is crestfallen, staying in his pose for hours on end.